A single-center experience with abiraterone as treatment for metastatic castration-resistant prostate cancer

Outcomes Following Abiraterone versus Enzalutamide for Prostate Cancer: A Scoping Review

Abiraterone acetate (AA) and enzalutamide (ENZ) are commonly used for metastatic prostate cancer. It is unclear how their outcomes and toxicities vary with patient-specific factors because clinical trials typically exclude patients with significant comorbidities. This study aims to fill this knowledge gap and facilitate informed treatment decision making. A registered protocol utilizing PRISMA scoping review methodology was utilized to identify real-world studies. Of 433 non-duplicated publications, 23 were selected by three independent reviewers. ENZ offered a faster and more frequent biochemical response (30-50% vs. 70-75%), slowed progression (HR 0.66; 95% CI 0.50-0.88), and improved overall survival versus AA. ENZ was associated with more fatigue and neurological adverse effects. Conversely, AA increased risk of cardiovascular- (HR 1.82; 95% CI 1.09-3.05) and heart failure-related (HR 2.88; 95% CI 1.09-7.63) hospitalizations. Ultimately, AA was associated with increased length of hospital stay, emergency department visits, and hospitalizations (HR 1.26; 95% CI 1.04-1.53). Accordingly, total costs were higher for AA, although pharmacy costs alone were higher for ENZ. Existing data suggest that AA and ENZ have important differences in outcomes including toxicities, response, disease progression, and survival. Additionally, adherence, healthcare utilization, and costs differ. Further investigation is warranted to inform treatment decisions which optimize patient outcomes.

Effectiveness of abiraterone acetate plus prednisone in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer in a large prospective real-world cohort: the ABItude study

Background:

Real-world data on chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone plus prednisone are limited, largely deriving from small retrospective studies.

Methods:

ABitude is an Italian, observational, prospective, multicenter study of mCRPC patients receiving abiraterone plus prednisone in clinical practice. Chemotherapy-naïve mCRPC patients were consecutively enrolled at abiraterone start (February 2016 to June 2017) and are being followed for 3 years, with evaluation approximately every 6 months. Several clinical and patients reported outcomes were examined.

Results:

In this second interim analysis, among 481 enrolled patients, 453 were evaluable for analyses. At baseline, the median age was 77 years and ~69% of patients had comorbidities (mainly cardiovascular diseases). Metastases were located mainly at bones and lymph nodes; 8.4% of patients had visceral metastases. During a median follow-up of 18 months, 1- and 2-year probability of radiographic progression-free survival were 73.9% and 56.2%, respectively; the corresponding rates for overall survival were 87.3% and 70.4%. In multivariable analyses, the number of bone metastases significantly affected radiographic progression-free survival and overall survival. During abiraterone plus prednisone treatment, 65% of patients had a ⩾50% prostate-specific antigen decline, and quality of life remained appreciably high. Among symptomatic patients according to the Brief Pain Inventory) (32%), scores significantly declined after 6 months of treatment. Overall, eight patients (1.7%) had serious adverse reactions to abiraterone.

Conclusions:

Abiraterone plus prednisone is effective and safe for chemotherapy-naïve mCRPC patients in clinical practice.

Clinical outcomes of abiraterone acetate and predictors of its treatment duration in metastatic castration-resistant prostate cancer: Real-world experience in the Southeast Asian cohort

It is of much interest to understand the efficacy of abiraterone acetate (AA) in routine clinical practice. We assessed the clinical outcome of AA in patients with metastatic castration-resistant prostate cancer (mCRPC) and determined clinical factors associated with AA treatment duration in real-world setting. This real-world cohort consisted of 93 patients with mCRPC treated with AA in Thailand (58.1%) and Malaysia (41.9%). Primary endpoints were overall survival (OS) and biochemical progression-free survival (bPFS). Secondary endpoints were predictors associated with AA treatment duration evaluated with Cox proportional hazards regression. Around 74% were chemotherapy-naïve. The median AA treatment duration was 10 months (IQR 5.6-17.1). Malaysians had a relatively lower median OS and bPFS (OS 17.8 months; 95% CI 6.4-29.1, bPFS 10.4 months; 95% CI 8.8-12.0) compared to Thais (OS 27.0 months; 95% CI 11.3-42.7, bPFS 14.0 months; 95% CI 5.8-22.2), although it did not achieve statistical significance (P > .05). Patients with longer AA treatment duration (>10 months) had lower risk of death and longer bPFS, compared to those with shorter AA treatment duration (≤10 months) (hazard ratio [HR] 0.10, 95% CI 0.05-0.22 and HR 0.13, 95% CI 0.06-0.25, respectively). Multivariable analysis showed that PSA at AA initiation, presence of PSA response and chemotherapy-naive were independently associated with AA duration (P < .05). Abiraterone acetate is well-tolerated in the Southeast Asian cohort with comparable survival benefits to other Asian populations in real-world setting. Lower PSA levels at AA initiation, presence of PSA response, and chemotherapy-naive were significant in determining AA treatment duration.

Real-world outcome with abiraterone acetate plus prednisone in Asian men with metastatic castrate-resistant prostate cancer: The Singapore experience

INTRODUCTION

Several small studies have reviewed the efficacy of abiraterone acetate plus prednisolone (AAP) in clinical practice outside a trial setting. We report the largest cohort study of clinical outcomes in metastatic castrate-resistant prostate cancer (mCRPC) patients treated with AAP in a multicenter multiracial clinical setting.

METHODS

A retrospective analysis on mCRPC patients treated at four tertiary hospitals in Singapore from 2012 to 2017 was conducted. Disease characteristics, treatment outcomes, and adverse events were retrieved from electronic medical records. Primary clinical end-point was overall survival (OS). A subset analysis of patients with various variables and OS curves were generated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Out of 200 patients with mCRPC treated with AAP, 163 (81.5%) patients were chemo-naïve (CN) and 37 (18.5%) patients were postchemotherapy (PC), with the median age of 68 (34-87) and 65 (52-80) years, respectively. Median OS was 20.0 (95% CI, 18.3-22.9) and 10.5 months (95% CI, 1.1-40.5) for CN and PC cohorts, respectively. A subset analysis of 108 patients showed a significantly longer OS in patients who had prior ADT for more than 12 months in CN patients (P < 0.001). Incidences of G3/G4 events were around 6.6%; most common side effect being hypertension with an incidence of 2.4%.

CONCLUSIONS

Treatment of CN and PC patients with AAP was associated with a comparable OS and progression-free survival to the reported series. Patients who were responsive to prior ADT of 12 months or more were associated with an improved OS.

Abiraterone acetate plus prednisone for the Management of Metastatic Castration-Resistant Prostate Cancer (mCRPC) without prior use of chemotherapy: report from a large, international, real-world retrospective cohort study

Background

With the recent introduction of novel treatment options, real-world data from patients with metastatic castration-resistant prostate cancer (mCRPC) are required to better understand the impact on routine clinical practice. This study primarily aimed to describe the time to treatment failure (TTF) of mCRPC patients treated with abiraterone acetate plus prednisone or the corticosteroid of choice (AAP) in the pre-chemotherapy setting. Other relevant outcomes, clinical and treatment characteristics of these patients were also evaluated.

Methods

This retrospective, observational study collected data from chemotherapy-naïve mCRPC patients treated with AAP from four European countries. Kaplan-Meier curves were used to estimate TTF, progression-free survival (PFS), and time to first skeletal-related event. The impact of baseline characteristics on TTF and PFS was explored using univariate and multivariate Cox proportional hazard models. Log-rank test was used to assess the potential role of duration of response to ADT in predicting response to AAP treatment.

Results

Data from 481 eligible patients (Belgium: 68; France: 61; Germany: 150; UK: 202) were analysed. At AAP initiation, the median age of patients was 75.0 years (interquartile range [IQR]: 69.0–81.0), and the median PSA was 56.2 ng/mL (IQR: 22.2–133.1), with over 50% of patients presenting an ECOG score of 0 or 1. Visceral metastases were present in 7.5% of patients; an exclusion criterion in the COU-AA-302 clinical trial. The median TTF with AAP was 10.0 months (95%CI: 9.2–11.1) and the median PFS was 10.8 months (95%CI: 9.6–11.8). Shorter TTF was significantly associated with higher ALP (> 119 units/L), higher PSA (> 56.2 ng/mL), or poorer ECOG PS scores at AAP initiation (p < 0.05). Patients with longer duration of response to ADT (≥12 months) presented longer TTF and longer time to progression (p < 0.0001).

Conclusions

This European real-world study provides valuable insights into the characteristics, treatment, and outcomes of chemotherapy-naïve patients with mCRPC who received AAP in routine clinical practice. Treatment effectiveness of AAP in the real-world is maintained despite patients having poorer clinical features at initiation than those observed in the COU-AA-302 trial population.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5280-6) contains supplementary material, which is available to authorized users.

Real-World Effectiveness of Palbociclib Versus Clinical Trial Results in Patients With Advanced/Metastatic Breast Cancer That Progressed on Previous Endocrine Therapy

Objective:

The aim of this study was to assess the real-world effectiveness and tolerability of palbociclib combined with endocrine therapy for the treatment of hormone receptor positive (HR-positive), human epidermal growth factor receptor 2 negative (HER2-negative), advanced/metastatic breast cancer that progressed on previous endocrine therapy, and to compare these results with the outcomes of the PALOMA-3 clinical trial.

Methods:

This study was a retrospective observational cohort study including all patients who started with palbociclib in the St. Antonius Hospital between September 1, 2016 and April 1, 2018 for the treatment of HR-positive, HER2-negative advanced/metastatic breast cancer that progressed on previous endocrine therapy. Individual patient data were collected from electronic medical records. Primary study outcomes were progression-free survival (PFS) and the number of permanent treatment discontinuations before disease progression due to adverse events (AEs). Secondary outcomes were the frequency of all (serious) AEs and the frequency of and reasons for dose reductions, -interruptions and cycle delays.

Results:

A total of 46 patients were studied with a median follow-up of 13.0 months. Overall, the median PFS in real-world clinical practice was 10.0 months (95% confidence interval (CI) 4.9-15.1), compared with 9.5 months in PALOMA-3 (95% CI 9.2-11.0). Two patients discontinued treatment because of AEs. Neutropenia was the most frequent grade 3-4 AE, but with no febrile neutropenia events. Most AEs were managed with palbociclib dose modifications. Regarding these modifications, more cycle delays, less dose reductions, and less dose interruptions occurred in clinical practice compared with PALOMA-3 (59 vs 36%, 22 vs 34%, and 9 vs 54%, respectively). Patients who did not meet the PALOMA-3 study eligibility criteria (n = 16) showed a lower median PFS of 5.5 months (95% CI 4.7-6.4).

Conclusions:

The effectiveness and tolerability of palbociclib in real-world clinical practice corresponded well with the results obtained in the PALOMA-3 clinical trial. Despite the differences in dose modifications, this study suggests that there is no efficacy-effectiveness gap in this patient population.

Abiraterone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: a systematic review of 'real-life' studies

Background

To assess the efficacy and safety of treatment with abiraterone acetate (AA) in chemotherapy-naïve men with metastatic castration-resistant prostate cancer (mCRPC) in the 'real-life' setting.

Methods

Data acquisition on the outcomes of the use of AA in chemotherapy-naive patients with mCRPC was performed by a MEDLINE comprehensive systematic literature search using combinations of the following key words: 'prostate cancer', 'metastatic', 'castration resistant', 'abiraterone', 'real life', and excluding controlled clinical trials (phase II and III studies). Identification and selection of the studies was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were overall survival (OS), progression-free survival (PFS), 12-week 50% reduction in prostate-specific antigen (PSA), and grade 3 and higher adverse events. Data were narratively synthesized in light of methodological and clinical heterogeneity.

Results

Within the eight identified studies that fulfilled the criteria, a total of 801 patients were included in the meta-analysis. Baseline PSA ranged between 9.5 and 212.0 ng/ml. Most of the patients had bone metastases. Duration of treatment with AA was longer in the studies with lower baseline PSA levels. The median OS ranged between 14 and 36.4 months. The PFS, assessed according to different definitions, ranged from 3.9 to 18.5 months. A 50% PSA reduction at 12 weeks was reached by a variable percentage of patients ranging from 36.0% to 62.1%. Finally, the rate of grade 3 and higher adverse events was reported in three studies and ranged from 4.4% to 15.5%.

Conclusions

Despite the high grade of heterogeneity among studies, treatment with AA seems to ensure good survival outcomes in the 'real-life' setting. However, prospective studies based on patients' characteristics being more similar to 'real-life' patients are necessary.

Safety and efficacy of abiraterone acetate in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: an Italian multicenter "real life" study

BACKGROUND

To evaluate the safety and efficacy of abiraterone acetate (AA) in the "real life" clinical practice for men with chemotherapy-naïve metastatic castration-resistant prostate.

METHODS

A consecutive series of patients with mCRPC in 9 Italian tertiary centres treated with AA was collected. Demographics, clinical parameters, treatment outcomes and toxicity were recorded. The Brief Pain Inventory scale Q3 was tracked and patient treatment satisfaction was evaluated. Survival curves were estimated by the method of Kaplan-Meier and Cox regression and compared by the log-rank test statistic.

RESULTS

We included 145 patients (mean age 76.5y). All patients were on androgen deprivation therapy. Patients had prior radiotherapy, radical prostatectomy, both treatments or exclusive androgen deprivation therapy in 17%, 33%, 9% and 40%, respectively. 57% of the patients had a Gleason score higher more than 7 at diagnosis. 62% were asymptomatic patients. The median serum total PSA at AA start was 17 ng/mL (range 0,4-2100). The median exposure to AA was 10 months (range 1-35). The proportion of patients achieving a PSA decline ≥50% at 12 weeks was 49%. Distribution of patient satisfaction was 32% "greatly improved", 38% "improved", 24% "not changed", 5.5% "worsened". Grade 3 and 4 toxicity was recorded in 17/145 patients 11.7% (70% cardiovascular events, 30% critical elevation of AST/ALT levels). At the last follow-up, median progression free and overall survival were 17 and 26.5 months, respectively. Both outcomes significantly correlated with the presence of pain, patient satisfaction, PSA baseline and PSA decline.

CONCLUSIONS

The AA is effective and well tolerated in asymptomatic or slightly symptomatic mCRPC in a "real life" setting. The survival outcomes are influenced by the presence of pain, patient satisfaction, baseline PSA and PSA decline.

TRIAL REGISTRATION

The study was retrospectively registered at ISRCTN as DOI: 10.1186/ISRCTN 52513758 in date April the 30th 2016.